MC 6460
12:30
-
1:30
pm
Speaker
Aaron Yip, Chemical Engineering, University of Waterloo
Title
Rational manipulation of microbial communities for degrading PET plastic
Abstract
Microplastics are a contaminant of global concern that pose risks to ecosystems and human health. Focusing on PET plastics, we present a proof-of-concept for reduction of microplastic pollution: in situ engineering of bacteria to biodegrade PET. We chose to focus on engineering bacteria in municipal wastewater because wastewater treatment plants are a major pathway by which microplastics enter natural ecosystems. Using a broad-host-range conjugative plasmid, we enabled various bacterial species from wastewater to secrete FAST-PETase, an engineered PET hydrolase that rapidly depolymerizes PET plastics at mesophilic temperatures. We found that FAST-PETase purified from the top-performing isolates could degrade about 40% of a 0.25 mm thick PET film within four days at 50 °C. We also demonstrate partial degradation of post-consumer PET over 5-7 days without enzyme purification by using spent culture supernatant from top-performing isolates. To better understand the efficacy of an in situ gene delivery approach, we are developing predictive models for horizontal gene transfer dynamics of our broad-host-range plasmid in structured microenvironments. Collectively, our work has broad implications for addressing the global plastic pollution problem by enabling bacteria from the environment to degrade PET in situ.